For certain applications, such as launch vehicle tracking, a full view of the complete sky is not always available using a single antenna. For example, a Global Positioning System (GPS) receiver may not be able to receive signals from an adequate number of satellites to perform an accurate position computation. When this is the case, multiple antennas may be required.
FIG. 1 shows a receiving system 100 that utilizes two antennas 102 and 104, mounted on a launch vehicle 106, configured with a combiner 108 and a single GPS receiver 110 as shown. FIG. 2 shows a receiving system 200 that utilizes multiple antennas 202 and 204, mounted on a launch vehicle 206, configured with an equal number of GPS receivers (or correlators) 208 and 210, respectively. FIG. 5 shows an example of typical antenna pattern coverage 500 provided by the receiver system 100. FIG. 6 shows an example of typical antenna pattern coverage 600 provided by the receiver system 200.
As between the two systems, the receiving system 100 (FIG. 1) is the least expensive approach, but leads to signal drop-outs due to the antenna interference patterns (FIG. 5). The receiving system 200 (FIG. 2) can provide better antenna pattern coverage (FIG. 6) than the receiving system 100, but is likely to be more expensive because multiple GPS receivers or correlators are required.
It would be useful to be able to provide a receiving system solution that is simpler and less expensive than using multiple correlators or receivers, and minimizes the interference problem associated with combining the signals from multiple antennas into a single receiver.